Authorities searching for Brittany Killgore, a California woman who disappeared Friday, arrested a woman on suspicion of murder and then located a dead body based upon leads stemming from the arrest, officials said.

The body, which has not been formally identified, was found near Lake Skinner in Riverside County, Calif., the San Diego County Sheriff's Department said.

The suspect, Jessica Lynn Lopez, who police said was 27, was arrested at a Ramada Inn in San Diego this morning and then treated for an undisclosed medical condition at a local hospital, the San Diego County Sheriff's Department said.

Authorities expected to charge her with murder after her release.

They would not disclose her relationship to Killgore, KGTV and other local media reported.

The developments came after Killgore's estranged husband said he would return home from Afghanistan, where he is an active duty Marine, to help in the search for his wife.

Killgore, of Fallbrook, Calif., filed for a divorce from her husband, Cory Killgore, also 22, just days before she disappeared Friday evening.

Police said they believe 45-year-old Marine Louis Ray Perez may have been the last person to see Killgore alive. Perez was arrested Sunday on an unrelated charge of possession of an AR-15 assault rifle and is being held in San Diego Central Jail on $500,000 bail.

"Mr. Perez was not cooperative or what we felt was fully forthcoming in his interview," said Lt. Larry Nesbit of the San Diego Sheriff's Office.

"He's being actively investigated for this murder," Nesbit told ABC News station KABC-TV in Los Angeles.

Killgore told friends she was going to spend Friday evening in San Diego's Gaslamp Quarter. However, authorities believe she never made it. Her cell phone was recovered in the area by San Diego trolley security,

Police declined to say whom Killgore planned to spend the evening with or the nature of her relationship with Perez.

Killgore was last seen wearing a dark purple evening gown with purple floral glitter patterns. She is a white female, 5-foot-7, 130 pounds with brown hair and brown eyes, according to the sheriff's department.

More than two dozen deputies searched for clues in a canyon area near Killgore's home as well as in her apartment on Monday.

Christopher Oglesby, a friend who lives in the same apartment complex as the Killgores, described them as "a very loving couple."

"I could say they liked to hang out with one another, but his job made it hard for him to sometimes be able to find the time," he said.